Prevalence Of Hemoglobin Variants Research Articles

Povišena srednja zapremina eritrocita u anemiji srpastih ćelija - jedna priča, previše?

Abstract: Introduction: Sickle cell disease is a hereditary blood disorder characterized by defective hemoglobin. Red cell indices are proposed as potential tools for diagnosing and managing sickle cell disorders. Materials and Methods: This study aimed to assess the utility of red cell indices as screening tools for sickle cell anemia. One hundred consenting adults of both sexes participated. Haematological parameters, including packed cell volume, hemoglobin values, hemoglobin electrphoretic patterns, and red blood cell count, were examined. Mean cell volume (MCV), mean cell hemoglobin concentration (MCHC), and mean cell hemoglobin (MCH) were calculated. Data analysis was performed using GraphPad Prism Software Version 9, with statistical significance set at p < 0.05 (95% confidence interval). Results: Haemoglobin values were significantly lower in Hb SS subjects (5.68 ± 1.7g/dl) compared to Hb AA (11.30 ± 1.5 g/dl) and Hb AS groups (11.03 ± 1.4 g/dl) (F = 32.279; p < 0.00001). The pattern was consistent with PCV and RBC values. Among the red blood cell indices assessed, only MCV showed a significant elevation (95.7 ± 2.4 fl) in the HbSS group compared to other groups (F = 4.165; p = 0.0183). No statistically significant difference was observed in MCHC and MCH values between the three groups (F = 0.5373, p > 0.586 for MCHC; F = 0.607, p > 0.546 for MCH). The prevalence of haemoglobin variants was as follows: HbAA (77%), HbAS (19%), and HbSS (4%). Conclusion: This study highlights significant reductions in haemoglobin values in Hb SS subjects and a notable elevation in MCV values in the Hb SS blood group. Elevated MCV in sickle cell anemia, where red cells are typically microcytic, warrants further investigation for differential diagnosis.

Prevalence of Haemoglobin Variants and Haemoglobinopathies in a Single Paediatric Centre in Southern India: A Retrospective Cross-sectional Study

Introduction: Haemoglobinopathies are qualitative disorders of Haemoglobin (Hb) resulting from structural defects in the amino acid sequence of one of the globin chains, whereas, thalassaemia results from quantitative defects in the synthesis of one or more of the globin chain subunits of the Hb tetramer. Cation Exchange- High Performance Liquid Chromatography (CE-HPLC) is one of the methods for initial screening of Hb variants like HbS, HbD, HbE etc and for quantification of HbF, HbA and HbA2 levels. Aim: To find out the prevalence of haemoglobinopathies in patients of a Government paediatric tertiary care hospital in south India. Materials and Methods: In this retrospective, cross-sectional study, all laboratory requests, in the period from August 2019 to July 2021, for Hb variant analysis by HPLC were collected, irrespective of provisional diagnosis. The Hb variant analysis was carried out by CE-HPLC on the Bio-Rad D-10 analyser. This study was conducted in a Government Paediatric tertiary care hospital in Southern India for patients who had any clinical or familial suspicion of haemoglobinopathies. The Statistical analysis was performed using Microsoft Excel 2010. Results: Total data of 704 laboratory requests for Hb Variant analysis were obtained. Out of 704 laboratory request, 585 were from children younger than 12 years of age and 119 were parental screening. There were 164 abnormal chromatograms. Out of 164 patients, 91 were female patients and 73 were male patients. Out of 164 abnormal chromatograms, 97 (59.15%) were beta- thalassaemia trait, 18 (10.98%) were beta-thalassaemia major, 13 (7.93%) were sickle cell trait, 2 (1.22%) were sickle cell disease, 21 (12.80%) were HbE trait, 2 (1.22%) were homozygous HbE, 2 (1.22%) were HbD trait, 3 (1.83%) were Hereditary Persistence of Foetal Hb (HPFH)/delta beta-thalassaemia, 2 (1.22%) were HbJ trait, 1 (0.61%) was HbE beta-thalassaemia, 1 (0.61%) was sickle- beta-thalassaemia and 2 (1.22%) were alpha thalassaemia. Conclusion: From this study, beta-thalassaemia trait and beta- thalassaemia major were found to be the first and second most prevalent haemoglobinopathies in children below 12 years of age. This data suggests the importance of premarital and antenatal screening procedures that can help in reducing the possibility of such haemoglobinopathies in the future generation, suffering and burden of disease to the family and society.

Compound heterozygosity for hemoglobin S and hemoglobin E in a family of Proto-Australoid origin: a case report

BackgroundHemoglobin S and E are commonly occurring hemoglobin variants among distinctly separate tribal populations of Central and Northeast India, respectively. Combined heterozygosity for hemoglobin S and E or hemoglobin SE disease is a benign clinical condition with rare incidence. Reports of approximately 46 hemoglobin SE cases are available worldwide. We conducted a screening program to study the prevalence of hemoglobin variants among the tribal population working in the tea estates of Northeast India. A total of 551 subjects were screened, and complete blood count was performed. Based on their hematological profiles, hemoglobin typing was done for 218 subjects.Case presentationWe describe a case of an adolescent male of Munda tribe diagnosed as double heterozygous for hemoglobin S and E. On screening of the nuclear family of the subject, the mother was found to have hemoglobin E disease and father as hemoglobin S trait. Both siblings of the subject were diagnosed as hemoglobin E trait.ConclusionThis is the first case of compound heterozygous for hemoglobin S and E to be reported from the tea tribes of Assam, India.

Hemoglobinopathies: An update on the prevalence trends in Southern Saudi Arabia.

Objectives:To investigate trends in hemoglobinopathies following the establishment of a mandatory premarital screening program (MPMSP) in the southern region of Saudi Arabia, where they are considered highly predominant.Methods:A retrospective analysis was performed on data from 32,130 high-performance liquid chromatography (HPLC) tests between November 2017 and October 2020. The data was obtained from the Hematology section, Laboratory Department, Armed Forces Hospital, Southern Region.Results:Despite the establishment of the MPMSP, our data showed that sickle cell disease remains a predominant hemoglobinopathy accounting for more than 7% of total tests in Southern Saudi Arabia. Observed HPLC hemoglobin fractions among the tested population showed a reduction in Hb A mean indicating a high rate of hemoglobin abnormalities. In addition, the prevalence of hemoglobin variants, including sickle cell and thalassemia, was higher in the younger population born after the MPMSP than in older subjects.Conclusion:Even with the implementation of the MPMSP, hemoglobin abnormalities remain prevalent in southern Saudi Arabia. A longer time frame is recommended to verify the validity of the program.

Surveillance for sickle cell disease, United Republic of Tanzania

ObjectiveTo determine the regional- and district-level newborn prevalence of sickle cell trait and disease, and the prevalence of haemoglobin variants and genetic modifiers of sickle cell disease, in the nine regions of north-western United Republic of Tanzania.MethodsWe repurposed dried blood spot samples from children (aged 0–24 months) born to mothers living with human immunodeficiency virus (HIV), collected as part of the HIV Early Infant Diagnosis programme, for sickle cell diagnosis. We performed isoelectric focusing to determine whether samples had normal haemoglobin, sickle cell trait, sickle cell disease or a rare haemoglobin variant. We shipped samples diagnosed as disease or variant to Cincinnati Children’s Hospital in the United States of America for deoxyribonucleic-acid-based analyses to determine the prevalence of α-thalassaemia, glucose-6-phosphate dehydrogenase (G6PD) deficiency or fetal haemoglobin genetic modifiers.FindingsWe analysed a total of 17 200 specimens during February 2017–May 2018. We observed a prevalence of sickle cell trait and disease of 20.3% (3492/17 200) and 1.2% (210/17 200), respectively. District-level trait varied from 8.6% (5/58) to 28.1% (77/274). Among confirmed sickle cell disease specimens, we noted 42.7% (61/143) had 1-gene deletion and 14.7% (21/143) had 2-gene deletion α-thalassaemia trait. We documented G6PD A– deficiency in 19.2% (14/73) of males.ConclusionOur calculated prevalence is twice as high as previously reported and reinforces the need for enhanced sickle cell diagnostic services. Our district-level data will inform public health policy, allowing screening and disease-modifying hydroxyurea therapy to be focused on high-prevalence areas, until universal newborn screening is available.

Blood Donors' Age, Haemoglobin Type, G6PD Status, and Blood Group Impact Storability of CPDA-1 Banked Whole Blood: A Repeated-Measure Cohort Study in Cape Coast, Ghana.

Background The high prevalence of haemoglobin variants and glucose 6-phosphate dehydrogenase disorder (G6PDd) in sub-Saharan Africa means that substantial proportions of donor blood units carry these red cell abnormalities. Aim This study investigated the impact that inherited haemoglobin variants and/or G6PD status have on whole blood banked at 4–6°C for 35 days. Method This repeated-measure cohort study was undertaken on 103 donor blood units collected into blood bag containing CPDA-1 anticoagulant. On days 0, 7, 14, 21, and 35, full blood count, osmotic-induced haemolysis, and plasma K+ levels were estimated. Also, on day 0, G6PD status, haemoglobin variants, % foetal haemoglobin, and blood group of donor units were determined using methaemoglobin reductase, cellulose acetate electrophoresis, modified Bekte alkali denaturation assay, and slide haemagglutination test, respectively. Result Overall, although plasma K+ levels increased during storage, donor units from individuals ≥20 years, G6PD normal, Hb AC, or blood group B had comparatively higher percentage change in plasma K+ during storage. Osmotically induced haemolysis of donor units was significantly decreased in Hb AC (compared with Hb A or AS) donor units on days 7, 14, 21, and 35 (p < 0.0001 in each case). G6PDd donor units had comparatively reduced osmotic-induced lysis compared with G6PD normal units, reaching a statistical significance on day 35 (p = 0.043). Also, Hb AC units had comparatively nonstatistically higher plasma K+ at all time points (compared with Hb A or AS). Furthermore, whereas donor units from individuals ≥20 years showed significantly higher median free haemoglobin on day 21 (compared to donor <20 years), when donor units were stratified per Hb variants, only Hb AS units had median free haemoglobin below the 0.8% threshold after 35 days' storage. Conclusion Age of donor, blood group, Hb AC variant, and G6PD status may be important considerations in the storability of whole blood.

Geospatial Mapping of Sickle Cell Disease in Northwest Tanzania: The Tanzania Sickle Surveillance Study (TS3)

Tanzania ranks third in Africa for the estimated number of annual births with sickle cell disease, but these estimates are based on sparse data from small studies reported over the past 50 years. A recently completed surveillance study from Uganda documented substantial variation in the prevalence of sickle cell trait and disease across the country. Tanzania lacks a national newborn screening program, and no contemporary multi-regional screening of infants has been undertaken. We designed and conducted a prospective study to determine the prevalence of sickle cell trait and disease by region and district in northwest Tanzania, where the prevalence of sickle cell is thought to be highest. The study used existing public health infrastructure while building local capacity for accurate diagnosis of sickle cell disease. Secondary objectives included characterization of hemoglobin variants and exploration of associations between sickle cell trait, sickle cell disease, malaria, and HIV.The Tanzania Sickle Surveillance Study (TS3) is a prospective cross-sectional study of HIV-exposed infants born in 9 regions across the Lake Zone of northwest Tanzania. In Tanzania, the HIV early infant diagnosis (EID) program collects dried blood spots (DBS) from all children born to HIV-infected mothers. DBS are transported to a central laboratory for prompt detection of HIV vertical transmission. In northwest Tanzania, the DBS are transported to Bugando Medical Centre, a teaching and consultancy hospital in Mwanza, where they are tested for HIV and then stored on-site, and thus available for further testing. Isoelectric focusing (IEF) equipment was donated to Bugando Medical Centre along with reagents and supplies. Two laboratory staff were trained by a board certified hematologist, and then attended a two day seminar by the IEF manufacturer. One pediatrician completed a 2-month observership at Cincinnati Children's Hospital. All DBS samples were tested by IEF using appropriate controls. Completed gels were scored independently by two Tanzanian staff members as normal, disease, trait, variant, or uninterpretable. DBS samples scored as disease or variant were repeated for confirmation and preserved for later genotyping. Regular Skype calls were convened with US-based collaborators to improve quality and interpretation. HIV test results were obtained from the local EID program.Between February 2017 and May 2018, 232 IEF gels were completed by the local staff. After children >24 months of age were excluded to obtain a more accurate newborn prevalence, the median age of children tested was 52 days (IQR 41-93 days), and a total of 17,278 unique DBS samples were scored. The quality of laboratory testing was extremely high with only 20 samples scored as uninterpretable and 54 with missing results, and the primary analysis was performed on the 17,204 remaining samples. The overall prevalence of sickle cell trait and disease in the entire cohort was 20.3% and 1.2%, respectively, with a 0.1% prevalence of hemoglobin variants. This corresponds to an allelic frequency of 0.114 for the sickle gene mutation and demonstrates perfect Hardy-Weinberg equilibrium. No HbC or other common beta-globin variants were identified. Geospatial mapping revealed some variation across regions, with sickle trait ranging from 16.6% to 22.5% and disease ranging from 0.5% to 1.5%. Analysis of individual districts with >100 samples revealed wider geographic variability, with sickle trait ranging from 15.2% to 27.8% and disease ranging from 0.0% to 4.3%. Co-morbidity between HIV and sickle cell disease was analyzed to compare it with the effect on mortality previously observed in Uganda. The prevalence of sickle cell disease was the same among HIV-infected and HIV-negative children (1.2%), suggesting no difference in mortality.The prevalence of sickle cell trait and disease among infants born in northwest Tanzania is very high, exceeding 20% trait and 1.2% disease. All regions in the Lake Zone are affected possibly due to lack of immigration to the area and similar environmental exposures. Targeted newborn screening can be started in high prevalence districts, using existing public health infrastructure with minimal start-up cost and training. Future work will evaluate the correlation between historical malaria prevalence and sickle cell prevalence, and identify hemoglobin variants. [Display omitted] DisclosuresWare:Addmedica: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Research Funding; Agios: Other: advisory board; Global Blood Therapeutics: Other: advisory board; Biomedomics: Research Funding; Nova Laboratories: Consultancy.

Prevalence of hemoglobin variants and hemoglobinopathies using cation-exchange high-performance liquid chromatography in central reference laboratory of India: A report of 65779 cases.

CONTEXT:Hemoglobinopathies constitute the world's most common genetically inherited red blood cell disorder. Screening and accurate identification of hemoglobin (Hb) variants have become increasingly important in antenatal diagnosis and prevention of Hb disorders.AIM:The aim of this study was to screen and identify Hb fractions prevalent in the Central Reference Laboratory of India.MATERIALS AND METHODS:A total of 65,779 cases were screened for hemoglobinopathies on the bio-rad variant high-performance liquid chromatography (HPLC) system by beta-thalassemia short program. The retention times, proportion of the hemoglobin (%) and the peak characteristics for all hemoglobin fractions were recorded. Molecular analysis of the beta-globin gene was carried out by DNA sequencing on eight cases.RESULTS:Total number of abnormal Hb fractions on cation exchange-HPLC (CE-HPLC) was seen in 12,131 (18.44%) cases. Beta-thalassemia trait was the predominant genetic Hb disorder accounting for 7377 cases (11.21%) of the total cases. This was followed by sickle cell trait (2.01%), sickle cell disease (1.59%), beta-thalassemia syndrome (0.80%), HbE trait (0.79%), and borderline HbA2 (0.51%). Molecular characterization of eight rare cases of hemoglobin variants by beta-globin gene sequencing identified three cases of Hb Beth Israel, two cases of Hb Hofu trait, and one case each of Hb J Cambridge, Hb Mizunami, and Hb Sherwood Forest.CONCLUSION:Superior resolution, rapid assay time, and accurate quantification make CE-HPLC suitable for the routine investigation of hemoglobinopathies.

Molecular basis and hematological features of hemoglobin variants in Southern Thailand

Hemoglobinopathy (abnormal hemoglobin or hemoglobin variant) is an inherited disorder that results in the abnormal structure of globin chains of the hemoglobin (Hb) molecule. Many abnormal Hbs have been characterized worldwide, including more than 20 variants in Thailand. The Bio-Rad Variant II HPLC system is used for investigating hemoglobin variants at Songklanagarind Hospital. This system has been shown to be a sensitive, specific, and reproducible method, but some hemoglobin variants such as Hb Tak and Hb D-Punjab cannot, as yet, be clearly separated by this method. The aim of this study was to investigate the prevalence of hemoglobinopathy in southern Thailand using DNA sequencing and study the severity of each hemoglobin variant. A total of 58 hemoglobin variant samples were obtained from blood samples undergoing routine hemoglobin typing at Songklanagarind Hospital. Genomic DNAs were extracted from the samples, and the globin genes were analyzed by using PCR-direct sequencing. The molecular analysis revealed eight hemoglobin variants: 28 Hb C, 12 Hb D-Punjab, 7 Hb Tak, 4 Hb G-Makassar, 2 Hb Lepore-Hollandia, 2 Hb Q-Thailand, 2 Hb O-Indonesia, and 1 Hb Hope. The distribution of hemoglobin variants in southern Thailand is associated with geographic and/or ethnic backgrounds. This study may help hematologists understand better the prevalence of hemoglobin variants and their hematological features in this region.

Prevalence of Haemoglobin Variants in Malaria Endemic Northeast India

Prevalence of Haemoglobin Variants in Malaria Endemic Northeast India

Prevalence of Haemoglobin Variants, ABO and Rhesus Blood Groups in Ladoke Akintola University of Technology, Ogbomoso, Nigeria

Prevalence of Haemoglobin Variants, ABO and Rhesus Blood Groups in Ladoke Akintola University of Technology, Ogbomoso, Nigeria